1. Field of the Invention
The present invention relates to an automatic gain control (AGC) circuit, and more particularly, to a digital AGC circuit which performs AGC by controlling a TOP voltage of an A/D converter.
2. Description of Related Art
An AGC circuit automatically controls a gain to give a constant output value at any time despite changes in input value. A conventional AGC circuit is made using an analog device. While, the conventional analog AGC circuit has no specific problem when used in an analog system, it is inconvenient to use in a digital system. Further, an AGC circuit which can perform a more accurate automatic gain control is needed. Meanwhile, an accurate AGC circuit, using mostly digital circuits, has been disclosed in a Korean patent No. 95-10063.